The main objectives of this proposal are to maintain an animal resource to promote, encourage, and expedite research into human prostatic adenocarcinoma. The resource has been in continuous existence for the past 15 years. Breeding colonies of Copenhagen line 2331 and Fischer F344 are maintained in a virus- free state. They are mated to produce an F1 hybrid. F1 animals are then inoculated with a spontaneous rat prostatic adenocarcinoma, R3327 for various human health related projects. This grant allows us to maintain this resource and to provide tumor bearing rats and/or tumor tissue to investigators for pilot projects. Because of the biological characteristics of this tumor including its slow growth rate, it would take an investigator approximately 18 months to gear-up for a pilot project without this resource. We are able to supply tumor bearing rate to investigators approximately 4-6 weeks after the request.